docs: def build_event_set(event):
      """
      Turn an EventStream event into a set of event types that ORES
      uses internally.
      """
      event_set = set()
      if re.match(r"([^\.]+.)?mediawiki\.revision-create$",
                  event['meta']['topic']):
          event_set.add('edit')
  
          user_groups = event.get('performer', {}).get('user_groups', [])
          if 'bot' in user_groups:
              event_set.add('bot_edit')
          else:
              event_set.add('nonbot_edit')
  
          if not event.get('rev_parent_id'):
              event_set.add('page_creation')
              if 'bot' in user_groups:
                  event_set.add('bot_page_creation')
              else:
                  event_set.add('nonbot_page_creation')
  
      return event_set